Novel heterocyclic compounds

ABSTRACT

Novel insecticidally active heterocyclic compounds of the formula ##STR1## wherein W represents a substituted pyridyl group, or a 5- or 6-membered optionally substituted heterocyclic group containing at least two hetero atoms selected from oxygen, sulfur and nitrogen atoms, 
     R represents a hydrogen atom or an alkyl group, 
     Y represents ═N--or ##STR2## R&#39; represents a hydrogen atom, an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group or a cyano group, 
     Z represents a nitro group or a cyano group, and 
     T represents 3 or 4 optionally substituted ring members of a 5- or 6-membered unsaturated heterocyclic ring which it forms together with the adjoining carbon atom and nitrogen atom, said 5- or 6-membered unsaturated heterocyclic ring containing 1 to 3 hetero atoms which are selected from oxygen, sulfur and nitrogen atoms and at least one of which is a nitrogen atom.

The present invention relates to novel heterocyclic compounds, to aprocess for their preparation, and to their use as insecticides.

It has alredy been disclosed that certain pyridine resonance hybridshave insecticidal activities (see U.S.Pat. No. 3,922,242) and thatcertain 1-substituted 1,2-dihydro-2-nitroimino pyridines have ananti-inflammatory activity (see J. Med. Chem., 1971, Vol. 14, No. 10,pp. 988-990).

There have now been found novel heterocyclic compounds of the formula(I)##STR3## wherein W represents a substituted pyridyl group or a 5- or6-membered optionally substituted heterocyclic group which has at leasttwo hetero atoms selected from oxygen, sulfur and nitrogen atoms.

R represents a hydrogen atom or an alkyl group,

Y represents ═N-- or ##STR4## R' represents a hydrogen atom, an alkylgroup, an aryl group, an acyl group, an alkoxycarbonyl group or a cyanogroup

Z represents a nitro group or a cyano group, and

T represents 3 or 4 optionally substituted ring members of a 5- or6-membered unsaturated heterocyclic ring which it forms together withthe adjoining carbon atom and nitrogen atom, said 5- or 6-memberedunsaturated heterocyclic ring containing 1 to 3 hetero atoms which areselected from oxygen, sulfur and nitrogen atoms and at least one ofwhich is a nitrogen atom.

The compounds of the formula (I) are obtained by a process in which

(a) compounds of the formula (II) ##STR5## wherein Y, Z and T are asdefined above, are reacted with compounds of the formula (III) ##STR6##wherein R and W are as defined above, and M represents a halogen atom orthe group --OSO₂ --R' in which R' represents an alkyl or aryl group, inthe presence of an inert solvent, if appropriate in the presence of abase.

The novel heterocyclic compounds of the formula (I) exhibit powerfulinsecticidal properties.

Surprisingly, the novel heterocyclic compounds according to theinvention exhibit a substantially greater insecticidal action thancompounds known from the aforesaid prior art, as shown in insecticidaltest examples given hereinafter.

Among the compounds according to the invention, of the formula (I),preferred compounds are those

in which

W is a pyridyl group having at least one substituent selected fromhalogen atoms, C₁ -C₄ alkyl groups optionally substituted by halogen, C₁-C₄ alkoxy groups optionally substituted by halogen, C₂ -C₄ alkenylgroups optionally substituted by halogen, C₁ -C₄ alkylsulfinyl groups,C₁ -C₄ alkylsulfonyl groups and C₃ -C₄ alkynyl groups, or a 5- or6-membered heterocyclic group which contains two hetero atoms selectedfrom oxygen, sulfur and nitrogen atoms, at least one of the hetero atomsbeing a nitrogen atom, and which may optionally be substituted by asubstituent selected from halogen atoms, C₁ -C₄ alkyl groups optionallysubstituted by halogen, C₁ -C₄ -alkoxy groups optionally substituted byhalogen, C₂ -C₄ alkenyl groups optionally substituted by halogen, C₁ -C₄alkylsulfinyl groups, C₁ -C₄ alkylsulfonyl groups and C₃ -C₄ alkynylgroups,

R represents a hydrogen atom or a methyl group,

Y represents ═N--,

Z represents a nitro group or a cyano group, and

T represents 3 or 4 ring members of a 5- or 6-membered unsaturatedheterocyclic ring which it forms together with the adjoining carbon atomand nitrogen atom, said 5- or 6-membered unsaturated heterocyclic ringcontaining 1 to 2 hetero atoms which are selected from sulfur andnitrogen atoms and at least one of which is a nitrogen atom, said 3 or 4ring members being optionally substituted by at least one of halogenatoms and C₁ -C₄ alkyl groups optionally substituted by halogen.

Very particularly preferred compounds of the formula (I) are those

in which

W represents a pyridyl group having one substituent selected fromfluoro, chloro, bromo, methyl, ethyl, trifluoromethyl, methoxy,trifluoromethoxy, vinyl, allyl, methylsulfinyl, methylsulfonyl andpropargyl, or a 5-membered heterocyclic group containing one oxygen orsulfur atom and one nitrogen atom and optionally being substituted byone substituent selected from fluoro, chloro, bromo, methyl, ethyl,trifluoromethyl, methoxy, trifluoromethoxy, vinyl, allyl,methylsulfinyl, methylsulfonyl and propargyl,

R represents a hydrogen atom or a methyl group,

Y stands for ═N--,

Z represents a nitro group or a cyano group, and

T represents 3 or 4 ring members of an imidazoline, thiazoline,dihydropyridine or dihydropyrimidine ring which it forms together withthe adjoining carbon atom and nitrogen atom, the ring members beingoptionally substituted by chloro or methyl.

Specific examples of the compounds (I) of the invention include

1-(2-chloro-5-pyridylmethyl)-2-nitroimino-1,2-dihydropyridine,

1-(2-chloro-5-pyridylmethyl)-5-methyl-2-nitroimino-1,2-dihydropyridine,

1-(3-methyl-5-isoxazolylmethyl)-2-nitroimino-1,2-dihydropyridine,

3-(2-chloro-5-pyridylmethyl)-2-nitroimino-4-thiazoline, and

1-(2-chloro-5-pyridylmethyl)-2-cyanoimino-1,2-dihydropyridine.

When 2-nitroimino-1,2-dihydropyridine and2-chloro-5-chloromethylpyridine are used as the starting materials inprocess (a), the reaction can be exemplified by the following scheme:##STR7##

In process (a), the compound of formula (II) means one based on theabove-given definitions of Y, Z and T.

In formula (II), Y, Z and T are preferably synonymous with the preferreddefinitions given above.

Formula (II) embraces both known and novel compounds.

The compound of formula (II) can exist in resonance structure as shownbelow; ##STR8##

In view of the above resonance structure, examples of the knowncompounds of formula (II) include 2-nitromethylpyridine and itsnuclearly alkyl substituted products described in J. Am. Chem. Soc.,vol. 91, pages 1856-1857; 4-nitromethylpyrimidine described in J. Org.Chem., vol. 37, pages 3662-3670; 3-nitromethyl-1,2,5-oxadiazoledescribed in Liebigs Ann. Chem., 1975, pages 1029-1050;2-pyridylacetonitrile described in J. Am. Chem. Soc., vol. 73, pages5752-5795; 5-imidazolylacetonitrile described in Chem. Abst., vol. 50,15516a; 2-imidazolylacetonitrile described in J. Med. Chem., vol. 11,pages 1028-1031; 2-pyrimidylacetonitrile, 2-thiazolylacetonitrile and4-thiazolylacetonitrile described in Japanese Laid-Open PatentPublication No. 49972/1974; 2-nitraminopyridine described in J. Med.Chem., vol. 14, pages 988-990; 5-chloro-2-nitraminopyridine described inBeilstein, 22II, page 519; methyl-substituted-2-nitraminopyridinedescribed in J. Am. Chem. Soc., vol. 77, pages 3154-3155;5-chloro-2-nitraminopyrimidine described in U.S. Pat. No. 3,041,339;3-methyl-6-nitraminopyridazine and 3-nitraminopyridazine described in J.Chem. Soc., 1950, pages 3236-3239; 3-chloro-6-nitraminopyridazinedescribed in Chem. Adst., vol. 55, 1634i; 2-nitraminothiazole describedin Can. J. Chem., vol. 31, pages 885-893;2-nitroimino-4-trifluoromethylthiazole described in J. Org. Chem., vol.20, pages 499-510; methyl-substituted-2-nitraminothiazole described inCan. J. Chem., vol. 34, pages 1261-1270; 4-nitramino- 1,2,3-thiadiazoledescribed in J. Chem. Soc., 1965, page 5175;3-methyl-5-nitramino-1,2,4-thiadiazole described in Belgian Pat. No.619423; 2-alkyl or -halogen substituted-5-nitramino-1,3,4-thiadiazoledescribed in J. Pharm. Soc. Japan, vol. 75, pages 1149-1150 or JapanesePatent Publication No. 9736/1977; 2-cyanaminopyridine described in Ann.Pharm. Fr., vol. 26, pages 469-472; 2-cyanomethylthiazole described inChem. Pharm. Bull., vol. 21, pages 74-86; 2-cyanaminopyrimidinedescribed in British Pat. No. 860,423; and 2-dicyanomethylpyridinedescribed in Chem. Ber., vol. 85, pages 397-407.

Ethyl 2-nitro-2-(2-pyridyl)acetate can be easily obtained by nitratingethyl 2-pyridylacetate in accordance with the method described in J.Org. Chem., vol. 37, pages 3662-3670.

In process (a), the compound of formula (III) as another startingmaterial means one based on the definitions of R, W and M.

In formula (III), R and W are preferably synonymous with the above-givenpreferred definitions, and M preferably represents chloro, bromo ortosyloxy.

The compounds of formula (III) are known, and typical examples are

2-chloro-5-chloromethylpyridine,

5-chloromethyl-3-methylisoxazole,

5-chloromethyl-2-chlorothiazole,

5-chloromethyl-2-methylthiazole,

5-chloromethyl-2-fluoropyridine,

2-bromo-5-chloromethylpyridine, and

5-chloromethyl-2-methylpyridine.

In effecting process (a), all inert organic solvents may be used assuitable diluents.

Examples of such diluents include water; aliphatic, alicyclic andaromatic hydrocarbons (optionally chlorinated) such as hexane,cyclohexane, petroleum ether, ligroin, benzene, toluene, xylene,methylene chloride, chloroform, carbon tetrachloride, ethylene chloride,and chlorobenzene; ethers such as diethyl ether, methyl ethyl ether,di-isopropyl ether, dibutyl ether, propylene oxide, dioxane andtetrahydrofuran; ketones such as acetone, methyl ethyl ketone, methylisopropyl ketone and methyl isobutyl ketone; nitriles such asacetonitrile, propionitrile ancd acrylonitrile; alcohols such asmethanol, ethanol, isopropanol, butanol and ethylene glycol; esters suchas ethyl acetate and amyl acetate; acid amides such as dimethylformamideand dimethylacetamide; sulfones and sulfoxides such as dimethylsulfoxide and sulfolane; and bases such as pyridine.

Examples of the base to be applied are inorganic bases such as sodiumhydroxide and potassium carbonate and organic bases such astriethylamine.

Process (a) can be practiced over a wide temperature range, for exampleat a temperature of about 0° to 120° C., preferably from about 20° toabout 80° C.

Preferably, the reaction is carried out under atmospheric pressure, butit is also possible to operate under elevated or reduced pressures.

In the practice of the above process, the desired compound of formula(I) can be obtained by reacting 1 mole of the compound of formula (II)with about 1.0 to 1.2 moles of triethylamine and about 1 to 1.2 moles,preferably 1 mole, of the compound of formula (III) in an inert solventsuch as ethanol.

The compound of formula (I) of this invention can assume a resonancestructure as shown below. ##STR9##

When the terminal of T on the C side is a nitrogen atom, the compound offormula (I) can also take the following resonance structure: ##STR10##

The active compounds are well tolerated by plants, have a favourablelevel of toxicity to warm-blooded animals, and can be used for combatingarthropod pests, especially insects which are encountered inagriculture, in forestry, in the protection of stored products and ofmaterials, and in the hygiene field. They are active against normallysensitive and resistant species and against all or some stages ofdevelopment. The above-mentioned pests include:

from the class of Isopoda, for example Oniscus asellus, Armadillidiumvulgare and Porcellio scaber;

from the class of the Diplopoda, for example Blaniulus guttulatus;

from the class of the Chilopoda, for example Geophilus carpophagus andScutigera spec.;

from the class of the Symphyla, for example Scutigerella immaculata;

from the order of the Thysanura, for example Lepisma saccharina;

from the order of the Collembola, for example Onychiurus armatus;

from the order of the Orthoptera; for example Blatta orientalis,Periplaneta americana, Leucophaea maderae, Blattella germanica, Achetadomesticus, Gryllotalpa spp., Locusta migrato ria migratorioides,Melanoplus differentialis and Schistocerca gregaria;

from the order of the Dermaptera, for example Forficula auricularia;

from the order of the Isoptera, for example Reticulitermes spp.;

from the order of the Anoplura, for example Phylloxera vastatrix,Pemphigus spp., Pediculus humanus corporis, Haematopinus spp. andLinognathus spp.;

from the order of the Mallophaga, for example Trichodectes spp. andDamalinea spp.;

from the order of the Thysanoptera, for example Hercinothrips femoralisand Thrips tabaci,

from the order of the Heteroptera, for example Eurygaster spp.,Dysdercus intermedius, Piesma quadrata, Climex lectularius, Rhodniusprolixus and Triatoma spp.;

from the order of the Homoptera, for example Aleurodes brassicae,Bemisia tabaci, Trialeurodes vaporariorum, Aphis gossypii, Brevicorynebrassicae, Cryptomyzus ribis, Aphis fabae, Doralis pomi, Eriosomalanigerum, Hyalopterus arundinis, Macrosiphum avenae, Myzus spp.,Phorodon humuli, Rhopalosiphum padi, Empoasca spp., Euscelis bilobatus,Nephotettix cincticeps, Lecanium corni, Saissetia oleae, Laodelphaxstriatellus, Nilaparvata lugens, Aonidiella aurantii, Aspidiotushederae, Pseudococcus spp. and Psylla spp.;

from the order of the Lepidoptera, for example Pectinophora gossypiella,Bupalus piniarius, Cheimatobia brumata, Lithocolletis blancardella,Hyponomeuta padella, Plutella maculipennis, Malacosoma neustria,Euproctis chrysorrhoea, Lymantria spp., Bucculatrix thurberiella,Phyllocnistis citrella, Agrotis spp., Euxoa spp., Feltia spp., Eariasinsulana, Heliothis spp., Spodoptera exiqua, Mamestra brassicae, Panolisflammea, Prodenia litura, Spodoptera spp., Trichoplusia ni, Carpocapsapomonella, Pieris spp., Chilo spp., Pyrausta nubilalis, Ephestiakuehniella, Galleria mellonella, Cacoecia podana, Capua reticulana,Choristoneura fumiferana, Clysia ambiquella, Homona magnanima andTortrix viridana;

from the order of the Coleoptera, for example Anobium punctuatum,Rhizopertha dominica, Acanthoscelides obtectus, Acanthoscelidesobtectus, Hylotrupes bajulus, Agelastica alni, Leptinotarsadecemlineata, Phaedon cochleariae, Diabrotica spp., Psylliodeschrysocephala, Epilachna varivestis, Atomaria spp., Oryzaephilussurinamensis, Anthronomus spp., Sitophilus spp., Otiorrhynchus sulcatus,Cosmopolites sordidus, Ceuthorrhynchus assimilis, Hypera postica,Dermestes spp., Trogoderma spp., Anthrenus spp., Attagenus spp., Lyctusspp., Meligethes aeneus, Ptinus spp., Niptus hololeucus, Gibbiumpsylloides, Tribolium spp., Tenebrio molitor, Agriotes spp., Conoderusspp., Melolontha melolontha, Amphimallon solstitialis and Costelytrazealandica;

from the order of the Hymenoptera for example Diprion spp., Hoplocampaspp., Lasius spp., Monomorium pharaonis and Vespa spp.;

from the order of the Diptera, for example Aedes spp., Anopheles spp.,Culex spp., Drosophila melanogaster, Musca spp., Fannia spp., Calliphoraerythrocephala, Lucilia spp., Chrysomyia spp., Cuterebra spp.,Gastrophilus spp., Hyppobosca spp., Stomoxys spp., Oestrus spp.,Hypoderma spp., Tabanus spp., Tannia spp., Bibio hortulanus, Oscinellafrit, Phorbia spp., Pegomyia hyoscyami, Ceratitis capitata, Dacus oleaeand Tipula paludosa.

In the field of veterinary medicine, the novel compounds of thisinvention are effective against various noxious animal parasites (endo-and ecto-parasites) such as insects and worms.

Examples of such animal parasites are insects such as Gastrophilus spp.,Stomoxys spp., Trichodectes spp., Rhodnius spp., and Ctenocephalidescanis.

The active compounds can be converted into the customary formulations,such as solutions, emulsions, suspensions, powders, foams, pastes,granules, aerosols, natural and synthetic materials impregnated withactive compound, very fine capsules in polymeric substances, coatingcompositions for use on seed, and formulations used with burningequipment, such as fumigating cartridges, fumigating cans and fumigatingcoils, as well as ULV cold mist and warm mist formulations.

These formulations may be produced in known manner, for example bymixing the active compounds with extenders, that is to say liquid orliquefied gaseous or solid diluents or carriers, optionally with the useof surface-active agents, that is to say emulsifying agents and/ordispersing agents and/or foam-forming agents. In the case water is usedas an extender, organic solvents can, for example, also be used asauxiliary solvents.

As liquid solvents diluents or carriers, there are preferably suitablearomatic hydrocarbons, such as xylene, toluene or alkyl naphthalenes,chlorinated aromatic or chlorinated aliphatic hydrocarbons, such aschlorobenzenes, chloroethylenes or methylene chloride, aliphatichydrocarbons, such as cyclohexane or paraffins, for example mineral oilfractions, alcohols, such as butanol or glycol as well as their ethersand esters, ketones, such as acetone, methyl ethyl ketone, methylisobutyl ketone or cyclohexanone, or strongly polar solvents, such asdimethylformamide and dimethyl-sulphoxide, as well as water.

By liquefied gaseous diluents or carriers are meant liquids which wouldbe gaseous at normal temperature and under normal pressure, for exampleaerosol propellants, such as halogenated hydrocarbons as well as butane,propane, nitrogen and carbon dioxide.

As solid carriers there may be used ground natural minerals, such askaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite ordiatomaceous earth, and ground synthetic minerals, such ashighly-dispersed silicic acid, alumina and silicates. As solid carriersfor granules there may be used crushed and fractionated natural rockssuch as calcite, marble, pumice, sepiolite and dolomite, as well assynthetic granules of inorganic and organic meals, and granules oforganic material such as sawdust, coconut shells, corn cobs and tobaccostalks.

As emulsifying and/or foam-forming agents there may be used non-ionicand anionic emulsifiers, such as polyoxyethylene-fatty acid esters,polyoxyethylene-fatty alcohol ethers, for example alkylaryl polyglycolethers, alkyl sulphonates, alkyl sulphates, aryl sulphonates as well asalbumin hydrolysis products. Dispersing agents include, for example,lignin sulphite waste liquors and methylcellulose.

Adhesives such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latices, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, can be used in theformulation.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs or metal phthalocyaninedyestuffs, and trace nutrients, such as salts of iron, manganese boron,copper, cobalt, molybdenum and zinc.

The formulations in general contain from 0.1 to 95 percent by weight ofactive compound, preferably from 0.5 to 90 percent by weight of activecompound.

The active compounds according to the invention can be present in theircommercially available formulations and in the use forms, prepared fromthese formulations, also in admixture with other active compounds, suchas insecticides, baits, sterilising agents, acaricides, nematicides,fungidides, growth-regulating substances or herbicides. The insecticidesinclude, for example, phosphates, carbamates, carboxylates, chlorinatedhydrocarbons, phenylureas, biologically active substances produces bymicroorganisms.

The active compounds according to the invention can furthermore bepresent in their commercially available formulations and in the useforms, prepared from these formulations, as a mixture with synergisticagents. Synergistic agent are compounds which increase the action of theactive compounds, without it being necessary for the synergistic agentadded to be active itself.

The active compound content of the use forms prepared from thecommercially available formulations can vary within wide limits. Theactive compound concentration of the use forms can be from 0.0000001 to100% by weight of active compound, preferably between 0.0001 and 1% byweight of active compound.

The compounds are employed in a customary manner appropriate for the useforms.

When used against hygiene pests and pests of stored products, the activecompounds are distinguished by an excellent residual action on wood andclay as well as by a good stability to alkali on limed substrates.

The following examples illustrate the present invention specifically.The present invention shall not be deemed to be limited to them alone.

PREPARATION EXAMPLES Example 1 ##STR11##

2-Chloromethylpyridine (3.24 g) and 2-nitraminopyridine (2.78 g) weredissolved in anhydrous ethanol (50 ml), and triethylamine (4.04 g) wasadded to the solution. The mixture was stirred at room temperature for awhile. Then, it was heated under reflux conditions for 8 hours. Thereaction mixture was cooled to room temperature, and poured into icewater. The precipitated crystals were collected by filtration, andrecrystallized from ethanol to give pale yellow1-(2-chloro-5-pyridylmethyl)-2-nitroimino-1,2-dihydropyridine (2.3 g) asthe desired compound. mp. 209°-212° C.

Example 2 ##STR12##

A mixture of 2-chloro-5-chloromethylpyridine (3.24 g),2-cyanaminopyrimidine (2.4 g), anhydrous potassium carbonate (3.04 g)and acetonitrile (100 ml) was refluxed for 5 hours under stirring. About50 ml of the acetonitrile were evaporated under reduced pressure, andthe residue was poured into ice water. The precipitated crystals werecollected by filtration, and recrystallized from ethanol to give1-(2-chloro-5-pyridylmethyl)-2-cyanomino-1,2-dihydropyrimidine (1.87 g)as colorless crystals. mp. 218°-220° C.

Table 1 below lists compounds of this invention obtained by the samemethods as described in Examples 1 and 2 together with the compoundsobtained in Examples 1 and 2.

                                      TABLE 1                                     __________________________________________________________________________     ##STR13##                                                                    Compound                                                                      No.   W          R  N side                                                                             T  C side                                                                             Y    Z                                       __________________________________________________________________________     1                                                                                   ##STR14## H  CHCHCHCH     N    NO.sub.2                                                                         mp. 209˜212° C.          2                                                                                   ##STR15## H                                                                                 ##STR16##   N    NO.sub.2                                                                         mp. 188˜190° C.          3                                                                                   ##STR17## H                                                                                 ##STR18##   N    NO.sub. 2                                                                        n.sub.D.sup.20 1.5939                 4                                                                                   ##STR19## H                                                                                 ##STR20##   N    NO.sub.2                                                                         mp. 84˜85° C.            5                                                                                   ##STR21## H                                                                                 ##STR22##   N    NO.sub.2                                                                         mp. 210˜217° C.          6                                                                                   ##STR23## H                                                                                 ##STR24##   N    NO.sub.2                                                                         mp. 229˜232° C.          7                                                                                   ##STR25## H                                                                                 ##STR26##   N    NO.sub.2                                                                         mp. 159˜160° C.          8                                                                                   ##STR27## H  CHCHCHCH     N    NO.sub.2                                                                         mp. 159˜161° C.          9                                                                                   ##STR28## H  CHCHCHCH     N    NO.sub.2                                                                         mp. 87˜88° C.           10                                                                                   ##STR29## H  CHCHS        N    NO.sub.2                                                                         mp. 219˜220° C.         11                                                                                   ##STR30## H  NCHS         N    NO.sub.2                                                                         mp. 166˜167° C.         12                                                                                   ##STR31## H                                                                                 ##STR32##   N    NO.sub.2                                                                         mp. 180˜183° C.         13                                                                                   ##STR33## H                                                                                 ##STR34##   N    NO.sub.2                                                                         mp. 167˜170° C.         14                                                                                   ##STR35## H                                                                                 ##STR36##   N    NO.sub.2                                                                         mp. 178˜180° C.         15                                                                                   ##STR37## H                                                                                 ##STR38##   N    NO.sub.2                                                                         mp. 90˜95° C.           16                                                                                   ##STR39## H                                                                                 ##STR40##   N    NO.sub.2                                                                         n.sub.D.sup.20 1.6335                17                                                                                   ##STR41## H  CHCHS        N    NO.sub.2                                                                         mp. 224˜227° C.         18                                                                                   ##STR42## H                                                                                 ##STR43##   N    NO.sub.2                                                                         mp. 137˜140° C.         19                                                                                   ##STR44## H                                                                                 ##STR45##   N    NO.sub.2                                                                         mp. 122˜124° C.         20                                                                                   ##STR46## H  CHCHCHCH     N    CN mp. 184˜186° C.         21                                                                                   ##STR47## H                                                                                 ##STR48##   N    CN mp. 215-219° C.               22                                                                                   ##STR49## H                                                                                 ##STR50##   N    CN                                      23                                                                                   ##STR51## H  CHCHS        N    CN mp. 151˜154° C.         24                                                                                   ##STR52## H  NCHS         N    CN mp. 122˜124° C.         25                                                                                   ##STR53## H  CHCHCHN      N    CN mp. 218˜220° C.         26                                                                                   ##STR54## H  CHCHCHCH     N    CN mp. 218˜219° C.         27                                                                                   ##STR55## H  CHCHCHCH     N    NO.sub.2                                28                                                                                   ##STR56## H  CHCHCHCH     N    NO.sub.2                                29                                                                                   ##STR57## CH.sub.3                                                                         CHCHCHCH     N    NO.sub.2                                30                                                                                   ##STR58## H  CHCHCHCH     N    NO.sub.2                                31                                                                                   ##STR59## H  CHCHCHCH     N    NO.sub.2                                32                                                                                   ##STR60## H  CHCHCHCH     N    NO.sub.2                                33                                                                                   ##STR61## H  CHCHCHCH     N    NO.sub.2                                34                                                                                   ##STR62## H  CHCHCHCH     N    NO.sub.2                                35                                                                                   ##STR63## H  CHCHCHCH     N    NO.sub.2                                36                                                                                   ##STR64## H  CHCHO        N    NO.sub.2                                37                                                                                   ##STR65## H  CHCHS        N    NO.sub.2                                38                                                                                   ##STR66## H  CHCHCHN      N    NO.sub.2                                39                                                                                   ##STR67## H                                                                                 ##STR68##   N    NO.sub.2                                40                                                                                   ##STR69## H  CHCHS        N    NO.sub.2                                41                                                                                   ##STR70## H  CHCHS        N    NO.sub.2                                42                                                                                   ##STR71## H  CHCHS        N    NO.sub.2                                43                                                                                   ##STR72## H  CHCHS        N    NO.sub.2                                44                                                                                   ##STR73## H  CHCHS        N    NO.sub.2                                45                                                                                   ##STR74## H  CHCHS        N    NO.sub.2                                46                                                                                   ##STR75## H  CHCHNH       N    NO.sub.2                                47                                                                                   ##STR76## H  CHCHCHN      N    NO.sub.2                                48                                                                                   ##STR77## H                                                                                 ##STR78##   N    NO.sub.2                                49                                                                                   ##STR79## H  CHCHCHCH     N    CN                                      50                                                                                   ##STR80## CH.sub.3                                                                         CHCHCHCH     N    CN                                      51                                                                                   ##STR81## H  CHCHCHCH     N    CN                                      52                                                                                   ##STR82## H                                                                                 ##STR83##   N    CN                                      53                                                                                   ##STR84## H  CHCHCHCH     N    CN                                      54                                                                                   ##STR85## H  CHCHCHCH     N    CN                                      55                                                                                   ##STR86## H  CHCHCHCH     N    CN                                      56                                                                                   ##STR87## H  CHCHCHCH     N    CN                                      57                                                                                   ##STR88## H  CHCHCHCH     N    CN                                      58                                                                                   ##STR89## H  CHCHCHCH     N    CN                                      59                                                                                   ##STR90## H  CHCHCHCH     N    CN                                      60                                                                                   ##STR91## H  CHCHCHCH     N    CN                                      61                                                                                   ##STR92## H  CHCHS        N    CN                                      62                                                                                   ##STR93## H  CHCHS        N    CN                                      63                                                                                   ##STR94## H  CHCHS        N    CN                                      64                                                                                   ##STR95## H   CHCHCHN     N    CN                                      65                                                                                   ##STR96## H                                                                                 ##STR97##   N    CN                                      66                                                                                   ##STR98## H  CHCHS        N    CN                                      67                                                                                   ##STR99## H  CHCHS        N    CN                                      68                                                                                   ##STR100##                                                                              H  CHCHCHN      N    CN                                      69                                                                                   ##STR101##                                                                              H  CHCHCHCH     CH   NO.sub.2                                70                                                                                   ##STR102##                                                                              H  CHCHCH CH    CH   NO.sub.2                                71                                                                                   ##STR103##                                                                              H  CHCHCHCH     CH   NO.sub.2                                72                                                                                   ##STR104##                                                                              H  CHCHCHCH     CH   NO.sub.2                                73                                                                                   ##STR105##                                                                              H  CHCHCHCH     CH   NO.sub.2                                74                                                                                   ##STR106##                                                                              H  CHCHCHN      CH   NO.sub.2                                75                                                                                   ##STR107##                                                                              H  CHNCHCH      CH   NO.sub.2                                76                                                                                   ##STR108##                                                                              H  ONCH         CH   NO.sub.2                                77                                                                                   ##STR109##                                                                              H  CHNCHCH      CH   NO.sub.2                                78                                                                                   ##STR110##                                                                              H  CHCHS        CH   NO.sub.2                                79                                                                                   ##STR111##                                                                              H  CHCHS        CH   NO.sub.2                                80                                                                                   ##STR112##                                                                              H  CHCHNH       CH   NO.sub.2                                81                                                                                   ##STR113##                                                                              H  CHCHCHCH     CH   CN                                      82                                                                                   ##STR114##                                                                              H  CHCHCHN      CH   CN                                      83                                                                                   ##STR115##                                                                              H  CHCHCHN      CH   CN                                      84                                                                                   ##STR116##                                                                              H  CH CHCHN     CH   CN                                      85                                                                                   ##STR117##                                                                              H  CHCHNH       CN   CN                                      86                                                                                   ##STR118##                                                                              H  CH.sub.2NCH  CH   CN                                      87                                                                                   ##STR119##                                                                              H  CHCHS        CH   CN                                      88                                                                                   ##STR120##                                                                              H  CHCHNH       N    NO.sub.2                                                                         mp. 186-189° C.               89                                                                                   ##STR121##                                                                              H  CHCHNH       N    NO.sub.2                                                                         mp. 156-157° C.               __________________________________________________________________________

BIOLOGICAL TESTS

Comparative Compounds ##STR122## (A-1, A-2 and A-3: the compoundsdescribed in Japanese Laid-Open Patent Publication No. 29,570/1975)##STR123## (the compound described in J. Med. Chem., 1971, vol. 14,pages 988-990).

Example 8 (Biological Test)

Test on Nephotettix cincticeps having resistance to organophosphorusagents:

Preparation of a Test Chemical

Solvent: 3 parts by weight of xylene

Emulsifier: 1 part by weight of polyoxyethylene alkyl phenyl ether

To form a suitable test chemical preparation, 1 part by weight of theactive compound was admixed with the aforesaid amount of the solventcontaining the aforesaid amount of the emulsifier. The mixture wasdiluted with water to a predetermined concentration.

Testing method

Onto rice plants, about 10 cm tall, planted in pots each having adiameter of 12 cm 10 ml per pot of the water-dilution of the activecompound was sprayed in a predetermined concentration prepared above.The sprayed chemical was dried, and a wire net having a diameter of 7 cmand a height of 14 cm was put over the rice plants, and 30 femaleimagoes of Nephotettix cincticeps showing resistance to organophosphorusagents were released into the net. The pots were each placed in aconstant temperature chamber and the number of dead insects was examined24 hours later, and the kill ratio was calculated.

In this test compounds 1, 2, 8, 10, 20, 23, 25, 26 exhibited a killratio of 100% at a concentration of 8 ppm of the active ingredient,whereas the comparison compounds A-1, A-3 and B-1 showed no effect at 40ppm and comparison compound A-2 showed no effect at a concentration of 8ppm.

Example 4 (Biological Test)

Test on planthoppers:

Testing procedure

Water dilution in a predetermined concentration of each active compound,prepared as in Example 3, was sprayed in an amount of 10 ml per pot ontorice plants, about 10 cm all, grown in pots each having a diameter of 12cm. After drying the sprayed chemical, a wire net having a diameter of 7cm and a height of 14 cm was put over each pot, and 30 female imagoes ofNilaparvata lugens were released into the net. The pots were placed inan incubator, and the number of dead insects was examined two dayslayer. The kill ratio was calculated.

By the same procedure as above, the kill ratios on Sogatella furciferaand organophorphorus-resistant Laodelphax striatellus were calculated.

In this test for instance compounds 1, 2, 8 and 10 according to thepresent patent application exhibited a kill ratio of 100% against N.lugens, L. Striatellus and S. furcifera at a concentration of 40 ppm ofthe active ingredient, whereas the comparison compounds A-1, A-2, A-3and B-1 were either ineffective or considerably less effective in theabove mentioned test systems.

Example 5 (Biological Test)

Test on Myzus persicae (green peach aphids) having resistance toorganophosphorus agents and carbamate agents:

Testing method

Green peach aphids which had been bred were inoculated on eggplantseedlings (black elongated eggplants), about 20 cm tall, grown inunglazed pots having a diameter of 15 cm (about 200 aphids perseedling). One day after the inoculation, a water dilution of eachactive compound at a predetermined concentration prepared as in Example3 was sprayed in a sufficient amount onto the plants using a spray gun.After the spraying, the pots were left to stand in a greenhouse at 28°C. Twenty-four hours after the spraying, the kill ratio was calculated.For each compound, the test was carried out through two replicates.

In this test system for instance compounds 1, 2, 8 and 10 according tothe present application exhibited a kill ratio of 100% at aconcentration of 200 ppm of the active ingredient, whereas thecomparison compounds A-1, A-2, A-3 and B-1 were either ineffective orconsiderably less effective against Myzus persicae.

It will be understood that the specification and examples areillustrative but not limitative of the present invention and that otherembodiments within the spirit and scope of the invention will suggestthemselves to those skilled in the art.

We claim:
 1. A heterocyclic compound of the formula ##STR124## wherein Qis at least one substituent selected from halogen atoms, C₁ -C₄ alkylgroups optionally substituted by halogen, C₁ -C₄ alkoxy groupsoptionally substituted by halogen, C₂ -C₄ alkenyl groups optionallysubstituted by halogen, C₁ -C₄ alkylsulfinyl groups, C₁ -C₄alkylsulfonyl groups and C₃ -C₄ alkynyl groups,R represents a hydrogenatom or a methyl group, Y represents ═N-- or ═CH--, Z represents a nitrogroup or a cyano group, and T represents 4 ring members of a 6-memberedunsaturated heterocyclic ring which it forms together with the adjoiningcarbon atom and nitrogen atom, said 6-membered unsaturated heterocyclicring optionally containing an additional ring nitrogen atom andoptionally substituted by at least one of halogen atoms and C₁ -C₄ alkylgroups optionally substituted by halogen.
 2. A compound according toclaim 1, whereinR represents a hydrogen atom or a methyl group, Yrepresents ═N--, and T represents 4 ring members of a 6-memberedunsaturated heterocyclic ring which it forms together with the adjoiningcarbon atom and nitrogen atom, said 6-membered unsaturated heterocyclicring optionally containing an additional ring nitrogen atom, said 4 ringmembers being optionally substituted by at least one of halogen atomsand C₁ -C₄ alkyl groups optionally substituted by halogen.
 3. A compoundaccording to claim 1, whereinQ represents one substituent selected fromfluoro, chloro, bromo, methyl, ethyl, trifluoromethyl, methoxy,trifluorometholxy, vinyl, allyl, methylsulfinyl, methylsulfonyl andpropargyl, R represents a hydrogen atom or a methyl group, Y stands for═N--, and T represents 4 ring members of a dihydropyridine ordihydropyrimidine ring which it forms together with the adjoining carbonatom and nitrogen atom, the ring members being optionally substituted bychloro or methyl.
 4. A compound according to claim 1, wherein suchcompound is1-(2-chloro-5-pyridylmethyl)-2-nitroimino-1,2-dihydropyridineof the formula ##STR125##
 5. A compound according to claim 1, whereinsuch compound is1-(2-chloro-5-pyridylmethyl)-2-cyanomino-1,2-dihydropyridine of theformula ##STR126##
 6. A compound according to claim 1, wherein##STR127## is a dihydropyridine or dihydropyrimidine ring.
 7. A compoundaccording to claim 1, wherein ##STR128## is a dihydropyridine ring.
 8. Acompound according to claim 1, wherein such compound is1-(2-chloro-5-pyridylmethyl)-5-methyl-2-nitroimino-1,2-dihydropyridineof the formula ##STR129##
 9. An insecticidal composition comprising aninsecticidally effective amount of a heterocyclic compound according toclaim 1 and a diluent.
 10. A method of combating insects which comprisesapplying to such insects or to an insect habitat an insecticidallyeffective amount of a heterocyclic compound according to claim
 1. 11.The method according to claim 12, wherein such compoundis1-(2-chloro-5-pyridylmethyl)-2-nitroimino-1,2-dihydropyridine,1-(2-chloro-5-pyridylmethyl)-5-methyl-2-nitroimino-1,2-dihydropyridine,1-(2-chloro-5-pyridylmethyl)-2-cyanoimino-1,2-dihydropyridine, or1-(2-chloro-5-pyridylmethyl)-2-cyanomino-1,2-dihydropyrimidine.